FKIE_CVE-2026-53357
Vulnerability from fkie_nvd - Published: 2026-07-02 15:17 - Updated: 2026-07-02 15:17
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: fix UAF in l2cap_sock_cleanup_listen() vs l2cap_conn_del()
bt_accept_dequeue() unlinks a not-yet-accepted child from the parent
accept queue and release_sock()s it before returning, so the returned
sk has no caller reference and is unlocked.
l2cap_sock_cleanup_listen() walks these children on listening-socket
close. A concurrent HCI disconnect drives hci_rx_work ->
l2cap_conn_del() which runs l2cap_chan_del() + l2cap_sock_kill() and
frees the child sk and its l2cap_chan; cleanup_listen() then uses both:
BUG: KASAN: slab-use-after-free in l2cap_sock_kill
l2cap_sock_kill / l2cap_sock_cleanup_listen / __x64_sys_close
Freed by: l2cap_conn_del -> l2cap_sock_close_cb -> l2cap_sock_kill
This is distinct from the two fixes already in this area: commit
e83f5e24da741 ("Bluetooth: serialize accept_q access") serialises the
accept_q list/poll and takes temporary refs inside bt_accept_dequeue(),
and CVE-2025-39860 serialises the userspace close()/accept() race by
calling cleanup_listen() under lock_sock() in l2cap_sock_release().
Neither covers l2cap_conn_del() running from hci_rx_work, so this UAF
still reproduces on current bluetooth/master.
Take the reference at the source: bt_accept_dequeue() does sock_hold()
while sk is still locked, before release_sock(); callers sock_put().
cleanup_listen() pins the chan with l2cap_chan_hold_unless_zero() under
a brief child sk lock (serialising vs l2cap_sock_teardown_cb()), drops
it before l2cap_chan_lock(), and skips a duplicate l2cap_sock_kill() on
SOCK_DEAD. conn->lock is not taken here: cleanup_listen() runs under
the parent sk lock and that would invert
conn->lock -> chan->lock -> sk_lock (lockdep).
KASAN/SMP: an unprivileged listen/close vs HCI-disconnect race produced
12 use-after-free reports per run before this change; 0, and no lockdep
report, over 1600+ raced iterations after it on bluetooth/master.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/bluetooth/af_bluetooth.c",
"net/bluetooth/iso.c",
"net/bluetooth/l2cap_sock.c",
"net/bluetooth/rfcomm/sock.c",
"net/bluetooth/sco.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "751de6ec671fe75ad9cf65a0638d2a06b6a5984d",
"status": "affected",
"version": "15f02b91056253e8cdc592888f431da0731337b8",
"versionType": "git"
},
{
"lessThan": "407217734835d21d4e0105ebf347860dc1806f88",
"status": "affected",
"version": "15f02b91056253e8cdc592888f431da0731337b8",
"versionType": "git"
},
{
"lessThan": "7eebd4c2c86f573af87ff165d08a83432eb0b919",
"status": "affected",
"version": "15f02b91056253e8cdc592888f431da0731337b8",
"versionType": "git"
},
{
"lessThan": "5d86d2f1b4d9a508c441d3e45277ae1a73cfed57",
"status": "affected",
"version": "15f02b91056253e8cdc592888f431da0731337b8",
"versionType": "git"
},
{
"lessThan": "87c543e2f78d0871f271df92dab98901bbd5b6f5",
"status": "affected",
"version": "15f02b91056253e8cdc592888f431da0731337b8",
"versionType": "git"
},
{
"lessThan": "added1213395071470a900cc845a042fb51882a6",
"status": "affected",
"version": "15f02b91056253e8cdc592888f431da0731337b8",
"versionType": "git"
},
{
"lessThan": "a5ca86a6097a8b030ca3226cd300b17ed330f966",
"status": "affected",
"version": "15f02b91056253e8cdc592888f431da0731337b8",
"versionType": "git"
},
{
"lessThan": "ab1513597c6cf17cd1ad2a21e3b045421b48e022",
"status": "affected",
"version": "15f02b91056253e8cdc592888f431da0731337b8",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/bluetooth/af_bluetooth.c",
"net/bluetooth/iso.c",
"net/bluetooth/l2cap_sock.c",
"net/bluetooth/rfcomm/sock.c",
"net/bluetooth/sco.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.7"
},
{
"lessThan": "5.7",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.259",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.210",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.175",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.142",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.92",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.34",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.0.*",
"status": "unaffected",
"version": "7.0.11",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: fix UAF in l2cap_sock_cleanup_listen() vs l2cap_conn_del()\n\nbt_accept_dequeue() unlinks a not-yet-accepted child from the parent\naccept queue and release_sock()s it before returning, so the returned\nsk has no caller reference and is unlocked.\n\nl2cap_sock_cleanup_listen() walks these children on listening-socket\nclose. A concurrent HCI disconnect drives hci_rx_work -\u003e\nl2cap_conn_del() which runs l2cap_chan_del() + l2cap_sock_kill() and\nfrees the child sk and its l2cap_chan; cleanup_listen() then uses both:\n\n BUG: KASAN: slab-use-after-free in l2cap_sock_kill\n l2cap_sock_kill / l2cap_sock_cleanup_listen / __x64_sys_close\n Freed by: l2cap_conn_del -\u003e l2cap_sock_close_cb -\u003e l2cap_sock_kill\n\nThis is distinct from the two fixes already in this area: commit\ne83f5e24da741 (\"Bluetooth: serialize accept_q access\") serialises the\naccept_q list/poll and takes temporary refs inside bt_accept_dequeue(),\nand CVE-2025-39860 serialises the userspace close()/accept() race by\ncalling cleanup_listen() under lock_sock() in l2cap_sock_release().\nNeither covers l2cap_conn_del() running from hci_rx_work, so this UAF\nstill reproduces on current bluetooth/master.\n\nTake the reference at the source: bt_accept_dequeue() does sock_hold()\nwhile sk is still locked, before release_sock(); callers sock_put().\ncleanup_listen() pins the chan with l2cap_chan_hold_unless_zero() under\na brief child sk lock (serialising vs l2cap_sock_teardown_cb()), drops\nit before l2cap_chan_lock(), and skips a duplicate l2cap_sock_kill() on\nSOCK_DEAD. conn-\u003elock is not taken here: cleanup_listen() runs under\nthe parent sk lock and that would invert\nconn-\u003elock -\u003e chan-\u003elock -\u003e sk_lock (lockdep).\n\nKASAN/SMP: an unprivileged listen/close vs HCI-disconnect race produced\n12 use-after-free reports per run before this change; 0, and no lockdep\nreport, over 1600+ raced iterations after it on bluetooth/master."
}
],
"id": "CVE-2026-53357",
"lastModified": "2026-07-02T15:17:03.103",
"metrics": {},
"published": "2026-07-02T15:17:03.103",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/407217734835d21d4e0105ebf347860dc1806f88"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/5d86d2f1b4d9a508c441d3e45277ae1a73cfed57"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/751de6ec671fe75ad9cf65a0638d2a06b6a5984d"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/7eebd4c2c86f573af87ff165d08a83432eb0b919"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/87c543e2f78d0871f271df92dab98901bbd5b6f5"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/a5ca86a6097a8b030ca3226cd300b17ed330f966"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/ab1513597c6cf17cd1ad2a21e3b045421b48e022"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/added1213395071470a900cc845a042fb51882a6"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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